Dennis Kirk is a mail-order company rerportedly under the ownership umbrella of LeMans Corp, which owns Parts Unlimited, the largest aftermarket distributor in the U.S. As such, they buy their tires a LOT cheaper than SW Moto does, which is only a dealer and must buy them at dealer cost from a company such as Parts Unlimited. So, when Dennis Kirk sells something at retail, they make the distributor's profit AND they make the dealer's profit. When they have to match a dealer's price (be it SW Moto or anyone else), they are still selling it to you at a greater profit than if they sold it to a dealer.
Personally, I like a good price, but I also like supporting dealers, whether they're local or far away like SW Moto. We need dealers to succeed so we have a place to shop and to take our bikes for those service items we can't do ourselves. To support Parts Unlimited through Dennis Kirk, is to encourage them to screw over the very dealers that they sell their products to, by taking advantage of their distributor's purchase price to undercut their very own customers (dealers). That, to me, doesn't pass the smell test. That's why I NEVER, NEVER, EVER buy anything from Dennis Kirk.
YMMV.